Finite Element Analysis of Electrically Excited Quartz Tuning Fork Devices

Quartz Tuning Fork (QTF)-based Scanning Probe Microscopy (SPM) is an important field of research. A suitable model for the QTF is important to obtain quantitative measurements with these devices. Analytical models have the limitation of being based on the double cantilever configuration. In this paper, we present an electromechanical finite element model of the QTF electrically excited with two free prongs. The model goes beyond the state-of-the-art of numerical simulations currently found in the literature for this QTF configuration. We present the first numerical analysis of both the electrical and mechanical behavior of QTF devices. Experimental measurements obtained with 10 units of the same model of QTF validate the finite element model with a good agreement.

Terror cognoscitivo y terror metafísico en la obra de Jorge Luis Borges

Los cuentos de Jorge Luis Borges pertenecen, de algún modo, al género de la literatura de terror. No en un sentido estricto, claro está, pero tampoco en un sentido meramente metafórico. Ciertamente, los cuentos que integran Ficciones o El Aleph aterrorizan a todo el mundo, pues muchos no los leen por miedo de no entenderlos y el resto, al leerlos, se ven embargados por ese terror metafísico que provoca la violentación de nuestros modos de entender la realidad. Borges es, pues, un terrorista, pero un terrorista apaciguador, puesto que busca aterrorizarnos con el objetivo de liberarnos del miedo. Se trata, por así decirlo, de un miedo homeopático, de un purgante que ha de ser expulsado junto con todo aquello que buscaba eliminar. Mi intención es estudiar de qué modo podemos sostenerle la mirada a los cuentos de Borges, con el doble objetivo de posibilitar su lectura a aquellos que los evitan por miedo a no entenderlos y de ayudar a aquellos que osan leerlos a superar el miedo mediante el cual Borges pretende serenarnos.

Escepticismo y conservadurismo progresista en la obra de Jorge Luis Borges

A lo largo de más de dos milenios los pensadores escépticos han compartido concepciones políticas semejantes. El hecho de que muchos de estos rasgos sean reconocibles en Borges refuerza la interpretación escéptica de su obra que he defendido en mi tesis doctoral y en diversos artículos. Analizaré, en primer lugar, la actitud política, conservadora, tradicionalmente asociada al escepticismo; en segundo lugar, el modo en que Borges participa de dicho conservadurismo progresista; y, en tercer lugar, aquellas características del pensamiento borgeano que pueden llevarnos a considerarlo como un intelectual según la definición que propone del mismo Edward W. Said en Representations of the intellectual.

A Feedfordward Adaptive Controller to Reduce the Imaging Time of Large-Sized Biological Samples with a SPM-Based Multiprobe Station

The time required to image large samples is an important limiting factor in SPM-based systems. In multiprobe setups, especially when working with biological samples, this drawback can make impossible to conduct certain experiments. In this work, we present a feedfordward controller based on bang-bang and adaptive controls. The controls are based in the difference between the maximum speeds that can be used for imaging depending on the flatness of the sample zone. Topographic images of Escherichia coli bacteria samples were acquired using the implemented controllers. Results show that to go faster in the flat zones, rather than using a constant scanning speed for the whole image, speeds up the imaging process of large samples by up to a 4x factor.

El Jardín de Falerina, Francisco de Rojas Zorrilla, Antonio Coello Ochoa y Pedro Calderón de la Barca. Edición, introducción y notas de Felipe B. Pedraza Jiménez y Rafael González Cañal, (Barcelona: Octaedro, 2010)

Parece mentira que una pieza teatral firmada por Calderón de la Barca haya tardado más de tres cientos años en aparecer impresa y que sea ahora,en el 2010, cuando lo haga por primera vez. ¿A qué se debe esta falta de interés por la obra?La respuestanos la ofrecen Felipe B. Pedza Jiménez y Rafael González Cañal en el capítulo que abre el estudio preliminar de su edicion tulado«Razones de una sin razón»

Diagnostic and prognostic value of antibodies against chimeric fibrin/filaggrin citrullinated synthetic peptides in rheumatoid arthritis

Introduction: Evidence suggests that citrullinated fibrin(ogen) may be a potential in vivo target of anticitrullinated protein/peptide antibodies (ACPA) in rheumatoid arthritis (RA). We compared the diagnostic yield of three enzyme-linked immunosorbent assay (ELISA) tests by using chimeric fibrin/filaggrin citrullinated synthetic peptides (CFFCP1, CFFCP2, CFFCP3) with a commercial CCP2-based test in RA and analyzed their prognostic values in early RA. Methods: Samples from 307 blood donors and patients with RA (322), psoriatic arthritis (133), systemic lupus erythematosus (119), and hepatitis C infection (84) were assayed by using CFFCP- and CCP2-based tests. Autoantibodies also were analyzed at baseline and during a 2-year follow-up in 98 early RA patients to determine their prognostic value. Results: With cutoffs giving 98% specificity for RA versus blood donors, the sensitivity was 72.1% for CFFCP1, 78.0% for CFFCP2, 71.4% for CFFCP3, and 73.9% for CCP2, with positive predictive values greater than 97% in all cases. CFFCP sensitivity in RA increased to 80.4% without losing specificity when positivity was considered as any positive anti-CFFCP status. Specificity of the three CFFCP tests versus other rheumatic populations was high (> 90%) and similar to those for the CCP2. In early RA, CFFCP1 best identified patients with a poor radiographic outcome. Radiographic progression was faster in the small subgroup of CCP2-negative and CFFCP1-positive patients than in those negative for both autoantibodies. CFFCP antibodies decreased after 1 year, but without any correlation with changes in disease activity. Conclusions: CFFCP-based assays are highly sensitive and specific for RA. Early RA patients with anti-CFFCP1 antibodies, including CCP2-negative patients, show greater radiographic progression.

The use of cost per life year gained as a measurement of cost-effectiveness in Spain: a systematic review of recent publications

The objective of this study was to evaluate the methodological characteristics of cost-effectiveness evaluations carried out in Spain, since 1990, which include LYG as an outcome to measure the incremental cost-effectiveness ratio. METHODS: A systematic review of published studies was conducted describing their characteristics and methodological quality. We analyse the cost per LYG results in relation with a commonly accepted Spanish cost-effectiveness threshold and the possible relation with the cost per quality adjusted life year (QALY) gained when they both were calculated for the same economic evaluation. RESULTS: A total of 62 economic evaluations fulfilled the selection criteria, 24 of them including the cost per QALY gained result as well. The methodological quality of the studies was good (55%) or very good (26%). A total of 124 cost per LYG results were obtained with a mean ratio of 49,529 and a median of 11,490 (standard deviation of 183,080). Since 2003, a commonly accepted Spanish threshold has been referenced by 66% of studies. A significant correlation was found between the cost per LYG and cost per QALY gained results (0.89 Spearman-Rho, 0.91 Pearson). CONCLUSIONS: There is an increasing interest for economic health care evaluations in Spain, and the quality of the studies is also improving. Although a commonly accepted threshold exists, further information is needed for decision-making as well as to identify the relationship between the costs per LYG and per QALY gained.

J.I. Pozo y M. del P. Pérez: Psicología del aprendizaje universitario: La formación en competencias

Ressenya de: Juan Ignacio Pozo y Mª del Puy Pérez Echeverría (coords.) Psicología del aprendizaje universitario: la formación en competencias. Ediciones Morata, Madrid, 2009, 231 págs. ISBN: 978-84-7112-598-9.

Oncobiguanides: Paracelsus" law and nonconventional routes for administering diabetobiguanides for cancer treatment

The dose makes the poison, the common motto of toxicology first expressed by Paracelsus more than 400 years ago, may effectively serve to guide potential applications for metformin and related biguanides in oncology. While Paracelsus' law for the dose-response effect has been commonly exploited for the use of some anti-cancer drugs at lower doses in non-neoplastic diseases (e.g., methotrexate), the opposite scenario also holds true; in other words, higher doses of non-oncology drugs, such as anti-diabetic biguanides, might exert direct anti-neoplastic effects. Here, we propose that, as for any drug, there is a dose range for biguanides that is without any effect, one corresponding to"diabetobiguanides" with a pharmacological effect (e.g., insulin sensitization in type 2 diabetes, prevention of insulin-dependent carcinogenesis, indirect inhibition of insulin and growth factor-dependent cancer growth) but with minimal toxicity and another corresponding to 'oncobiguanides' with pharmacological (i.e., direct and strong anticancer activity against cancer cells) as well as toxic effects. Considering that biguanides demonstrate a better safety profile than most oncology drugs in current use, we should contemplate the possibility of administering biguanides through non-conventional routes (e.g., inhaled for carcinomas of the lung, topical for skin cancers, intravenous as an adjunctive therapy, rectal suppositories for rectal cancer) to unambiguously investigate the therapeutic value of high-dose transient biguanide exposure in cancer. Perhaps then, the oncobiguanides, as we call them here, could be viewed as a mechanistically different type of anti-cancer drugs employed at doses notably higher than those used chronically when functioning as diabetobiguanides

Evolución y retos de la educación virtual : construyendo el e-learning del siglo XXI

Las autoras y autores de este libro ofrecen una descripción de la evolución general del e-learning apuntando los elementos clave hacia los que debe ir evolucionando. Parten de la experiencia y la práctica contrastada con las investigaciones sobre el tema. A lo largo de los distintos capítulos nos muestran cómo vive un estudiante virtual, su papel y la manera en que plantea y organiza sus actividades; nos acercan al profesorado analizando su rol en el diseño de la formación y la comunicación con los estudiantes; hablan de la colaboración, analizando cómo diseñar actividades colaborativas y señalando sus ventajas y límites; describen los diferentes recursos de aprendizaje que podemos disponer en el diseño de los cursos y, por último, acompañan nuestra mirada hacia el futuro próximo analizando las tendencias y los retos a los que debemos hacer frente para construir el e-learning del siglo XXI.

La Transmisión textual de las Mémories de Philippe de Commynes en las traducciones de Felipe (1636) y Juan de Vitrián (1643)

Análisis de las traducciones de Felipe Vitrián (1936) y de Juan Vitrián (1643) de la obra de Philippe de Commynes “Mémoires”

González et al. Reply

A Reply to the Comment by K. E. Nagaev

Los métodos alternativos en el estudio de la seguridad de cosméticos

El Reglamento 1223/2009 establece las normas que deben cumplir todos los productos cosméticos comercializados en Europa, con objeto de velar por el funcionamiento del mercado interior y lograr un elevado nivel de protección de la salud humana garantizando el uso de métodos alternativos que no impliquen la utilización de animales. El Laboratorio Europeo de Referencia para las Alternativas a la Experimentación con Animales (EURL-EURL- ECVAM) es el laboratorio de referencia en Europa encargado de validar los métodos alternativos. Posteriormente pueden ser homologados por la Organización de Cooperación y Desarrollo Económico (OCDE). Por otro lado, el Comité Científico de Seguridad de los Consumidores (SCCS) asesora a la Comisión sobre todos los temas relacionados con la seguridad de los cosméticos. En esta revisión se detalla una relación de métodos alternativos necesarios para evaluar la seguridad de los ingredientes cosméticos así como los métodos usados y sus limitaciones.